| 摘要 |
PROBLEM TO BE SOLVED: To improve the control responsiveness, draw out a maximum output power with the high efficiency and suppress the cost of components. SOLUTION: The pulse widths PW of pulse train signals used for the PWM control 15 are monitored. If the fluctuation of the pulse width PW vanishes within a predetermined time, it is judged that the operation point of a solar cell 2 is on the open voltage side of a maximum power point on the output characteristic curve. On the other hand, if the fluctuation of the pulse width PW exists even after the predetermined time passes, it is judged that the operation point is on the short-circuit current side of the maximum power point and the inverter is so controlled as to make the operation point follow the maximum power point. |
